Voice operated relay circuits



June 16, 1931. B, G, BJQRNSQN 1,810,004-

voIcE OPERATED RELAY CIRCUITS Filed June. 1929 2 Sheets-Sheet 1a B. G.BJaRNso/v BV Jmmw A Tram/.EV

June 16, 1931. a. G. BJoRNsQN voIcE oPEnAjrEn RELAY CIRCUITS 2SheetSV-Sheet 2 Filed June 6. 1929 /N VEA/TUR B. G Bao/Ns oN TORNEYPatented June 16, 1931 vUNITED STATES PATENT OFFICE BJON G'.V BJORNSON,OF BROOKLYN, NEW YORK, ASSIGNOR T'O BELL TELEPHONE ,LABORATORIES,INCORPORATEDOF NEW YORK, N. Y., A CORPORATION F NEW YORK )roximatinfY aarticular fre uenc and the l e P a use of such an arrangement inconnection with local or other circuits to provide for rendering themoperative'and inoperative.

The invention is applicableV to any type of communication system inwhich accelerating and delay action devices are employed but hasespecial application to systems in which it is desirable to operate therelay device on intermittent pulses and the detailed description willrefer specifically to such a system.

One of the features of this invention consists in the method employed tosecure a socalled hangover7 time in the case of echo suppressors or theswitching `time in the case of voice operated repeaters When voicecurrents cease Without affecting adversely the time of operation of thisrelay when voice currents begin. I

In the prior art Where arelay circuit has been operated .from the outputof a detector or rectifier, it has been customary to employ a condenseror filter arrangement to smooth out the impulses. This will retardthe'tiine of operation of the circuit especially when the impulsefrequency is low and a large ca- 40 pacity is required to obtain asmooth current Wave. Another feature of this invention consists in themethod employed to obtain a very fast operation of the circuit onimpulses ot low frequency' Without contact chattering.

This is accomplished.l in the preferred embodiment of the inventionherein shown and described by providing a circuit employing 5e threerelays, wherein the firstimpulse will VOICE OPERATED RELAY CIRCUITS1929.A seriai No. 369,985.

break the normally closed contacts of the main relay and the auxiliaryrelay. When the normally closed contact of the auxiliary relay is brokena condenser discharges causing the main and auxiliary relays to fullyoperate. Full operation of the main relay causes the hangover relay tooperate. At the cessation of the impulse from the rectifier theauxiliary relay releases again charging the condenser. The main andauxiliary relays are held in the non-operated position until anotherimpulse from the rectifier repeats the cycle of operation justdescribed. The hangover relay remains operated for adefinite timeinterval after each impulse.

In the other embodiment of the invention herein shown and described onlytwo rela fs are employed. The first impulse from the rectifier causesthe normally closed contact of the main relay to open. W'hen thiscontact is opened a condenser discharges through another Winding on themain relay and also through a Winding on the second or operating'relay.This causes the main relay to completely operate thereby closing thenormally open contact on the main relay and breaking the normally closedcontact on the operating relay. When the normally open contact on themain relay is closed current flows from a source of potential throughanother Winding from the operating. relay which fully operates theoperating'relay and charges a second condenser. lVlien the impulse fromthe rectifier has been reduced sufficiently, the second condenserdischar s through a Winding on the operating reiiy holding it operatedfor a definite period of time. When the armature of the main relayreturns to its normal position, the first mentioned condenser chargesand tends to hold the armature of the main relay lirmly on the normallyclosed contact for a short time and also tends to make the armature ofthe operating relay return to its normal position. VThe charging periodof the `first mentioned condenser must be made short compared to thehangover time of the operating relay. Also, the charging currentof thefirst mentioned condenser must at no time exceed the discharge currentof the other condenser such as a oner since the operating relay is to beheld operated by the discharge current from the last mentionedcondenser.

The invention will be better understood by referring to the lellowingdetailed description and accompanying drawings wherein Figs. 1 and 2 arecircuit diagrams of divers embodiments oi" the invention, and Figs. 1.21and 2-i`1 illustrate the same embodiments shown in Figs. 1 andrespectively, showing the relays in schematic lorm to facilitate vtol.-lowing the des ription o'l the invention.

Referring to Fics. 1 and 1PA, L represents a normally disabledtransmission path path of a repeater, or the one-Way line ot Ll-Wirecircuit. In the operation o'l' such circuits, it is desirable, in orderto prevent siii iing` that apparatus shall be ope ated to put the pathin condition ttor transmission only during the time -when voice currentsare being transmitted in the direction indicated. In the case ot echosuppressors control relays would be bridged across the opposite h `ltol.1 the i-Wire circuit and would short-circuit it whenever speechpassed on the first side for a period long enough to avoid echoes, aff;shown 'lor example, in Vll. S. Patent No. 1,536,907 to d'. Mills, May 5,1925.

Relays 1, 2 and 3 and the equipment associated therewith are utilized toput the trans mission path L in condition Ylor transniission and todisable said path when desired. The voice operated equipment which isbridged across the path L ahead of the delay network a and whichcomprises the amplilicr 5, detector (3, band-pass filter 7 and detector8 has been .shown for purposes illustration only, as the presentinvention is not dependent on the use o t any particular type o'l' detector circuit. Detector circuits with which the present invention maybe advantageously employed are disclosed in U. S. Patent No. 1,749,841granted to `Nyquist March 1l, 1930.

Relays' 1, 2 and 3 are preterably polar relays. llelay 1 comprises ayoke 10, a permae nent magnet 12 associated with the yoke, windings 11,and 13, an armature 15, and contacts 16 and. 17, between which thearinature is arranged to swing. rlie armature is biased, by a retractilespring l-r, or other suitable means, away from the yoke 18, Whichbiasing normally maintains armature 15 in connection with contact 17.

Relay 2 comprises a yoke 20, a` permanent magnet 22 associated with theyoke, Wi ndings 21 and 23, an armature a5 and a contact 27. The armatureis biased, by a retractile spring 24 or other suitable means, away'troia the yoke leg 23, which biasing normally maintains the armature 25in connection with contact 27.

Relay 3 comprises a yoke 30, a permanent magnet 32 associLw .d with theyoke, a winding 31 and an armature and a contact 37.

The armature is biased, by a retractile spring 3st or othe suitablemeans, away 'from the yoke leg 33, which biasing normally maintains thearmature in connection With contact 37.

'Vinding 11 on relay 1 and Winding 21 on relay 2 are connected in seriesto the output oit the detector circuit S. 1Winding 13 on relay 1 andWinding 23 on relay 2 are connected in series from ground through acondenser L10 on one side and through a resistance111 to armature 25 onrelay 2 on the other side. Contact 27 on relay 2 is connected to oneside of a battery 42, the other side of which battery is connected toground. The resistance 11 is connected to one side of a resistance 113,the other side oi Which resistance 13 is connccted to ground. Thearmature 15 on relay 1 is connected to one side of the line L and toground, and the armature on relay 3 is connected to the other side ofline L. Contacts 17 on relay 1 and 37 0n relay 3 are connected together.The Winding 31 on relay 3 is shunted by a resistance 44.-, condenser Iland resistance 16 connected in series. Contact 16 on relay 1 isconnected to the junction of resistance 11G and Winding' 31 on relay 3.The junction of condenser lo and resistance 44's is connected to theunction of the battery .li-2 and Contact 27.

The operation oic the system is as follows. lillith the relays 1, 2 and3 unenergized in the positions shown, the line L is short-circuited bythe connection from one side o'l line L through armature 15 and contact17 on relay 1 and Contact 37 and armature on relay to the other side ofline L. YVhen the l'irst impulse of the detected currents, derived fromthe speech frequency currents transmitted over line L, are transmittedi'roin the output oit detector 8 through Winding 11 on relay 1 andwinding 21 on relay 2, the armatures 15 and 25 on relays 1 and 2respectivel are moved from their normal positions shown, armature 15breaking its connection with contact 17, thereby removing the shortcircuit from across the line L, and arnwture 25 breaking its connectionwith contact 27.

As soon as armature 25 breaks its connertion With Contact 27, condenserL10 dischargony through the circuit 'from ground, condenser 40, Winding13 on relay 1, winding 23 on relay 2, resistances i1 and i3 to ground,thereby aiding the armatures 15 and in moving toward the yoke legs 13and respecti rely.

Complete operation of relay 1 causes its armature 15 to make connection.-with contact 16, thereby completing a. circuit from ground througharmature 15, Contact 1G, u.: iding 3l oi relay 3, resistance el andbattery lo ground, which causes relay 3 to operate and br ak theconnection between armature 35 and Contact 37.

As soon as the impulse from detector 3 approaches zero amplitude and thecondenser lll.)

4() has discharged, relays 1 and 2 will release. lVhen the armature 25on relay 2 connects with Contact 27, a circuit is completed fromarmatures 15 and 25 on relays 1 and 2 respectively against theircorresponding contacts 17 and 27 without contact chattering taking placebetween the armatures and the contacts. After condenser 40 has fullycharged,the biasing means 14 and 24 hold armatures 15 and 25respectively in their normal positions shown until the next impulse isreceived from the detector 8. The charging time of condenser 40 can bemade shorter than its discharging time, since it charges throughresistance 41 and discharges through resistances 41 and 43 in series. Inthis manner the relays 1 and 3 are quickly restored to their normalpositions and ready to operate on a subsequent impulse from the detector8.

Relay 3 is arranged to hold in its operated position thereby maintainingthe line L in' an operative condition, during the operation andreleasing of relays 1 and 2, when the time interval between the impulsesreceived from the output of detector 8 is of short duration.

Each time. that relay 1 operates, the relay 3 receives a new impulsethrough the circuit from ground through armature 15 and contact 16 onrelay 1, winding 31 on relay 3, resistance 44 and battery 42 to ground.Also, each time relay 1 operates, the circuit from ground througharmature 15 and contact 16 on relay 1, resistance 46, condenser 45,battery 42 to ground, causes the condenser 45 to charge up. When relay 1releases and the circuit is opened at contact 16, the condenser 45 willdischarge through resistance 46, winding 31 of relay 3, and resistance44 thereby holding relay 3 in its operated .position,while relays 2 and3 are periodically operating and releasing as described above.

Relay 3`does not release when the v'condenser 45 is being charged for atthe same time the circuit from ground through battery 42, resistance 44,winding 31, contact 16 and armature 15 on relay 1 to ground, maintainsrelay 3 in an operated position.

In this manner the line L is put in operative condition as soon as thefirst impulse is transmitted from the output of detector 8 and ismaintained in an operated position as long as impulses are transmittedfrom the output of detector 8 in sufficiently short recurring intervals.

Referring to Figs. 2 and 2-A, relays 50 and 60 Vand the equipmentassociatedtherewith are utilized to control the transmission path L. Theamplifier detector 9- is preferably a double detector circuit such asshown in Fig. 1 which includes the amplifier 5, detector 6, band passfilter 7 and detector 8.

Relays and 60 are preferably polar relays similar to relays 1, 2 and 3shown in Fig. 1. Relay 50 has windings 51 and 53, and armature 55, andcontacts 56 and 57, between which contacts the armature is arranged toswing. The armature 55 is normally biased, by a retractiie spring 54 orother suitable means, away from the yoke leg 58 so that the armature 55is normally in connection with contact 57 and normally disconnected fromcontact 56.

Relay 60 has two windings, 61 and 63, an armature and contacts 66 and67, between which contacts the armature 65 is arranged to swing. Thearmature 65 is normally biased, by a retractile spring 64 or othersuitable means, away from the yoke leg 68 so that the armature 65 isnormally in connection with contact 67 and normally disconnected fromContact 66.

Winding 51 on relay 50 is connected to the output of the amplifierdetector 9. Winding 53 on relay 50 and winding 63 on relay 60 areconnected in series from ground through a resistance 7() on one side,and through a condenser 71, contact 57 armature 55, and a battery 72 toground lon the other side. A resistance 73 is connected from contact 57to ground. The normally open contact 66 on relay 60 is arranged toshort-circuit the winding 63 on relay 60 when this contact 66 is inconnection Awith the V,armature 65 by the operation of relay 60.

n Winding 61 onrelay 60 is connected from Contact 56 on relay 50Vthrough a resistance 74 on one side, and to` ground on the other side.A condenser 75 and a resistance 76 are connected in series, from groundto contact 56 on relay 50, so that the series connection of thecondenser 75 and resistance 76 is in shunt connection with the winding61.

The operation of this system is as follows. Y

With the relays 5() and 6() unenergized and their armatures in theposition shown, the lline L is short-circuited by the normally closedconnection through contact 67 and armature 65 on relay 60. The firstimpulse of the detected current from the output of amplifier detector 9is transmitted through winding 51 on relay 50, causing the armature 55to move toward the y yoke leg 58, thereby breaking the connectionbetween contact 57 and armature 55.

by putting l'ne L in an operative coinL and snitcl'i (36 clises, thereby"t short-circhiting the winding (SS on rela leihen the armature 55 onrelay 50 makes connection with contact 5G, a circuit cornpleted fromground through hatery T2, .mature Contact 5G, resstance 7e, and n'in ingGl on relay 6G to ground, thereby hou'.- ing the relay G() in itsoperated position, and another circuit is completed from `ground throughbattery 72, armature 55, Contact 56, resistance 76 and condenser T5 toground, thereby charging,- conc ensei' 75.

Vhen the current :trom the output o'l'" ainplilier detector 9 throughWinding 5l on relay approach es zero amplitude and the condenser 7l hasdischarge, the 1oiasing` me ans on relay 50 moves the arniatnre 55 awaytroin the yoke leg` 58, thereby lirez king the connection between thearmature 35 and co itact 5G. This causes condenser Z5 to dischargethrough the circuit including' the winding Gl on relay 60, and theresistances Tl and T6. rfliis condenser discharge current holds the arnaturo G5 on relay GO in its opera Led position.

l.Vlien the armature on relay 50 connects with contact 5T, condenser 7lcharges through the circuit troni ground tl rough battery T2, armature55, Contact 57, condenser 7l, winding;` 58 ou relay 50. armature 65,Contact GG and resistance to ground, therehy holding' the armature 55iirmly in contact with contact 5T a id preventing contact chatte 'ino'.

llhen the next impulse is transmitted through W'nding el from the outputot ampliiier detector 9 relay Si) is again operated in the same mannerWhica holds relay (50 in its operated position and again charges condenser as described above.

In this manner the line L is maintained operative as long` impulsestransmitted 'from the ampliiier detector 9 in suiiicieiitly shortrecurring` intervals.

T he 'invention is also capable. of other modilications and adaptationsnot specifically rei'orred to, aut included Within the scoglio oli theappended claims.

That is claimed is:

l. A viln'atinosystoni including' a main pola r relay and an auxiliarypolar relay, each ol said pola' relays havirf an armature, a i ot conhotween which said ari ature is adapted to snf'ingr. aiul an operatingWindineY and an accelerating winding` associated with said armature,said acceleratngr Wind i nir on said main relay connected in serios withsaid acceleratiiur winding' on said auxiliary relay across the zrinature and normally closed conta-:tt oi said auxiliary relay tosupplenient the action ot the operi-ting windings on the res iectiyerelays when the normally closed c 'act on said auxiliary relay isopened, a third polar relay having a Winding which is tra a signaloperated clyice comp rality of relays. i`

teni and initially energized by the i 't sin# nal current impulsetransmitted o i said system, another WiV ,ding on each ot" said certainrelays, said last nientioned windings connected in series with the ther,a condenser connected 'in series with sa:` last mentioned i'vindingggs,means i'or charging said condenser when .aid certain relayrl areunoporated, and in sans for discharginev sai d condenser thi-ouah aiolart mentioned windings when one of said eei ain relays operated,thereby fully operating said certain relays, another relay, means 'toro)eratiiigisaid other relay ai" one ot said certain relays has fullyoperated, means vfor releasingY said certain relays at the cess` tion ofsaid signal impulse, and a slow electrical circuit connected to saidother relay te prevent the release oit said other relay as long asimpulses are t 'ansmitted over said system ata predetermined rate.

3. ln an electrical communication system, a voice operated devicecomprising a main relay and an auxiliary relay, both ot said relaysarranged to he initially energized loy Voice currents transmitted ovesaid system, a condenser connected in series with winring's on saidrelays, a source oil' potential arranged to he connected in seriescondenser through a. normally closed contact on said auxiliary relay, adisch:ii-iriacircuit or said condenser including a high resista ice, athird relay, a Winding;1 on said third relay, aid Winding connected insei-ics 1with a source ot potential and a high resistance. means forenergizing said Winding' on said third relay, said means including aVcontact Which is closed when said main relay operated, and a condenserand a high resist: nce connected in shunt to the Winding on said thirdrelay and said second. mentioned high resistance.

Il. ln an electrical communication system. a vibrating relay arrangementincluding;l polar relays, each oit aid polar relays ha' fin an armature,and a pair of contacts between which said armature is adapted to swiufisaid armatures normally restino; on one oi said contacts, ope-,rating;`Windinefs associated With said armatures of certain oli said relays,accelerating;- windings on said certain relays bridged across theaii'mature and normally closed contacts o'lE one oit said certain relaysto supplement the action oi' the operating Cil windings on said certainrelays when the normally closed contact on one of said certain relays iso ened, another polar relay, means for operating said other polar relayafter one of said certain relays has operated, said means including thenormally open contact on one of said certain relays, and a slowelectrical circuit connected to said other relay to retard the releaseof said other relay.

5. In an electrical communication system, a signal operated device,comprisingI a plurality of relays, windings on certain of said relaysconnected to said communication system and initially energized by thefirst signal current impulse transmitted over said system, means foraccelerating the operation of said certain relays, said means includinga condenser associated with other windings on said certain relays, andmeans for causing said condenser to discharge through said lastmentioned windings, another relay having a winding, means for energizingsaid winding on said other relay when one of said certain relays isfully operated, means for releasing said certain relays at the cessationof said signal impulse, and a slow electrical circuit comprisingcapacitance and impedance associated with the winding on said lastmentioned relay to hold said last mentioned relay operated as long asimpulses are transmitted over said system at a predetermined rate.

6. In a relay circuit, a relay adapt-ed to be operated to and held inits operated position by a succession of current impulses, a winding onsaid relay, a condenser in circuit with said winding, means responsiveto the individual impulses of a succession of impulses for charging saidcondenser in response to the loe-` ginning of an impulse and for sendingcurrent through said winding in a direction to operate said relay, saidmeans allowing said condenser to discharge through said winding on thecessation of an impulse in a direction to hold the relay operated, saidmeans comprising a relay having a plurality of windings thereon, one ofsaid last mentioned windings being connected to the source of currentimpulses for operating said last mentioned relay at the beginning of animpulse,

and another of said windings being connected in series with a secondcondenser and a second winding on said irst mentioned relay for as-Sistina the operation of both of said relays.

7. Inn a transmission system, a transmission line, a relay adapted to beoperated to and held in its operated position by a succession of currentimpulses, a winding on said relay, a condenser in circuit with saidwinding, means including an auxiliary relay having an armature kickedback and forth in response to the individual impulses of a'successionof' impulses for charging said condenser in response to the beginning ofan impulse and for sending current through said winding in a directionto operate said relay, said means allowing said condenser to dischargethrough said winding on the cessation of an impulse, in a direction tohold said first mentioned relay operated, a contact on said auxiliaryrelay normally in connection with said armature on said auxiliary relay,normally closed contacts on said lirst mentioned relay, connections romsaid last mentioned contacts to said transmission line through saidarmature and said contact normally in connection therewith on saidauxiliary relay, for rendering said transmission line inoperative whenboth of said relays are unoperated and for rendering said transmissionline operative when said normally closed contacts on said irst mentionedrelay are open.

In witness whereof, I hereunto subscribe my name this 3d day of'J une,1929.

BJ ORN G. BJORNSON.

